Performance

The Lumix DMC-GX7 certainly does not disappoint in the performance department. It can start up and take its first shot in roughly 0.7 seconds, so you can react quickly when something interesting comes your way.

Focusing is nearly instantaneous, with the kit lens averaging around 0.1 seconds at both wide-angle and telephoto - very impressive. In dim light, things weren't that much slower, with only a slight drop in immediacy. Only in low contrast scenes in very dim lighting did focus begin to struggle, and times extended beyond one second. Continuous AF is speedy too, though you may notice the usual 'back-and-forth' effect that comes along with contrast-detect autofocus.

Shot-to-shot performance (in single exposure mode) was excellent, with delays hovering around the 0.4 - 0.5 second mark, regardless of the image quality setting.

Continuous Shooting and Buffering

There are four continuous shooting modes available on the GX7: super high, high, medium, and low. The last two support live view during shooting, while the first two do not. The super high mode uses the electronic shutter, which allows the GX7 to shoot at the rates you'll see below.

To test the GX7's continuous shooting performance, we used a SanDisk Extreme Pro SDHC card, which has a write speed of 95MB/sec. Below we'll take a look at the super high, high, and medium speeds, for both the mechanical and electronic shutter. Do note that the super high speed option is for JPEGs only.

Super High (JPEG only, electronic shutter)

Timing
JPEG Large/Fine
Raw
Raw+JPEG Fine
Frame rate 40 fps N/A
Number of frames 80 shots
Buffer full rate N/A
Write complete 15 secs

High (mechanical shutter)

Timing
JPEG Large/Fine
Raw
Raw+JPEG Fine
Frame rate 6.4 fps 4.8 fps 4.9 fps
Number of frames To card capacity 10 shots 9 shots
Buffer full rate * N/A 1.2 fps 1.3 fps
Write complete 5 secs 9 secs 11 secs
* Frame rate may stutter when buffer is full

High (electronic shutter)

Timing
JPEG Large/Fine
Raw
Raw+JPEG Fine
Frame rate 9.5 fps 9.2 fps 8.6 fps
Number of frames 22 shots 9 shots 8 shots
Buffer full rate * 5 fps 1.2 fps 1.5 fps
Write complete 8 secs 10 secs 10 secs
* Frame rate may stutter when buffer is full

Medium (mechanical shutter)

Timing
JPEG Large/Fine
Raw
Raw+JPEG Fine
Frame rate 4.1 fps 3.6 fps 3.5 fps
Number of frames To card capacity 11 shots 10 shots
Buffer full rate * N/A 1.3 fps 1.1 fps
Write complete 2 secs 9 secs 11 secs
* Frame rate may stutter when buffer is full

Medium (electronic shutter)

Timing
JPEG Large/Fine
Raw
Raw+JPEG Fine
Frame rate 4.0 fps 3.5 fps 3.5 fps
Number of frames To card capacity 11 shots 10 shots
Buffer full rate * N/A 1.5 fps 1.4 fps
Write complete 2 secs 9 secs 11 secs
* Frame rate may stutter when buffer is full

The Lumix DMC-GX7 met or exceeded Panasonic's speed estimates, except for high speed shooting with the electronic shutter, which couldn't quite break the 10 fps barrier.

While the camera is clearing its buffer, you can still take photos or enter the menu system, so you can keep shooting as needed, though the frame rate may be reduced.

Battery Life

The GX7 uses the DMW-BLG10 lithium-ion battery - used by a number of other Lumix mirrorless cameras - and it contains 7.4 Wh of energy. With the 14-42mm kit lens, battery life is estimated at 350 shots per charge using the CIPA standard. If you use the 20mm pancake lens, that number drops to 320 shots (presumably because the focus is harder to drive).

The battery is 'refilled' using an included external charger. It takes just over three hours to fully charge the BLG10.